This paper chronicles the evolution of load-sharing parameter estimation methodologies, with a particular focus on the significant contributions made by Kim and Kvam (2004) and Park (2012). Kim and Kvam's pioneering work underscored the inherent challenges in deriving closed-form solutions for load-share parameters, which necessitated the use of sophisticated numerical optimization techniques. Park's research, on the other hand, provided groundbreaking closed-form solutions and extended the theoretical framework to accommodate more general distributions of component lifetimes. This was achieved by incorporating EM-type methods for maximum likelihood estimation, which represented a significant advancement in the field. Unlike previous efforts, this paper zeroes in on the specific characteristics and advantages of closed-form solutions for load-share parameters within reliability systems. Much like the basic Economic Order Quantity (EOQ) model enhances the understanding of real-life inventory systems dynamics, our analysis aims to thoroughly explore the conditions under which these closed-form solutions are valid. We investigate their stability, robustness, and applicability to various types of systems. Through this comprehensive study, we aspire to provide a deep understanding of the practical implications and potential benefits of these solutions. Building on previous advancements, our research further examines the robustness of these solutions in diverse reliability contexts, aiming to shed light on their practical relevance and utility in real-world applications.

본 연구의 목적은 미국, 영국, 독일, 일본의 학교안전 법제를 살펴봄으로 써, 국내 학교안전에 시사하는 바를 논하고 제시하는 데에 있다. 외국사례를 통해 우리나라 학교안전사고 예방 및 학교안전관리시스템이 보다 실효성 있 게 작동하도록 몇 가지 적용 및 시사점을 제시하였다. 첫째, 학교 안전관리 책임을 명확히 하고 학교안전교육을 지원하는 법제의 명문화와 「학교폭력예 방법」, 「학교안전법」, 「학교보건법」을 「학교안전보건법」으로 통합할 필요가 있다. 둘째, 국가 책임을 강화하는 차원에서 충분한 예산 지원과 인력 확보 및 교직원의 안전 전문성 향상을 위한 제도 마련, 그리고 일원화된 전문기관 등이 필요하다. 셋째, 「학교안전법」을 「산업안전보건법」 수준으로 업그레이 드할 필요가 있고, 독일의 사회보험 수준으로 학교안전공제회의 역량을 제고 할 필요가 있다. 넷째, 체계적인 시스템과 실효성 있는 매뉴얼에 의해 작동되 도록 학교안전망을 촘촘하게 구축할 필요가 있다. 다섯째, 예방활동과 안전 교육의 패러다임을 전환할 필요가 있다. 여섯째, 평소 지역 유관기관·단체 등 과 안전시스템을 긴밀하게 공유, 연계할 필요가 있다. 일곱째, 실효성 있는 학교안전 위험성 평가를 실시하여 사고 발생률을 낮출 필요가 있다. 여덟째, 학교 보안을 더욱 강화할 필요가 있다. 아홉째, 학생안전 법제에 학생의 권리 와 의무를 함께 명시할 필요가 있다. 열 번째, 우리나라도 ‘갭 이어(Gap Ye ar)’ 제도 도입을 검토할 필요가 있다. 이상의 논의와 제시를 통해, 국내 학 교안전 및 학교안전 법제의 긍정적 변화를 기대한다.

This paper studied the problem of determining the optimal inventory level to meet the customer service target level in a situation where the customer demand for each branch of a nationwide retailer is uncertain. To this end, ISR (In-Stock Ratio) was defined as a key management indicator (KPI) that can be used from the perspective of a nationwide retailer such as Samsung, LG, or Apple that sells goods at branches nationwide. An optimization model was established to allow the retailer to minimize the total amount of inventory held at each branch while meeting the customer service target level defined as the average ISR. This paper proves that there is always an optimal solution in the model and expresses the optimal solution in a generalized form using the Karush-Kuhn-Tucker condition regardless of the shape of the probability distribution of customer demand. In addition, this paper studied the case where customer demand follows a specific probability distribution such as a normal distribution, and an expression representing the optimal inventory level for this case was derived.

Ensuring the safe arrival of delivery cargo at its intended destination is of utmost importance. Truck drivers play a crucial role in guaranteeing the secure delivery of cargo without any mishaps. However, there are various factors that may lead to delayed arrival of trucks at their destination, such as late departures or prolonged loading operations. The timely departure of cargo transportation is contingent upon several variables, including the driver's experience, cargo volume, and loading time. If the transportation commencement is delayed, it may increase the risk of accidents due to an elevated operating speed. Consequently, we conducted a study to investigate the correlation between cargo loading time, cargo volume, driving experience, and the likelihood of accidents. Our findings indicate that both cargo volume and driver experience can impact the likelihood of vehicle accidents. Furthermore, all factors can have an interactive effect on the occurrence of accidents. However, extending the loading time may mitigate the impact on the likelihood of accidents.

The purpose of this study is to suggest the characteristics of online shopping malls and find a way to establish a differentiated marketing Strategy for online shopping malls in China. This study investigated the effect on the loyalty by applying the perceived shopping value (Hedonic Value, Utilitarian Value) of consumers in online shopping malls. In addition, In order to grasp the factors affecting consumer loyalty in online shopping malls, the characteristics of online shopping malls are multidimensional, consisting of product characteristics, recommended quality, benefit services, and community services. In order to obtain the purpose of the study, a questionnaire was surveyed for chinese online shopping experience and the research model was verified through empirical analysis method. Statistical analysis program was used together with SPSS 24.0 and AMOSS 24.0. Looking at the results of the analysis, firstly, the recommended quality and benefit service of online shopping malls are positive for the perceived hedonic value of consumers. The product characteristics and community service were found to have no effect on the hedonic shopping value. Secondly, the product characteristics, recommended quality, benefit service, and community service of online shopping malls on the utilitrian value perceived by consumers were positively affected. Thirdly, the perceived hedonic value has a positive effect on loyalty. Finally, it was confirmed that perceived utilitrian value affects loyalty. Based on the results of this study, a differentiated marketing strategy was established for existing chinese online shopping mall operators and potential new operators as well.

목적 : 본 연구는 도로교통공단 장애인운전지원센터에서 2017년까지 운전면허를 취득한 장애인의면허취득 현황을 비교 및 분석하고, 이를 바탕으로 향후 국내 장애인 운전과 관련된 제반사항에 대한 개선방안을 도출하는데 그 목적이 있다. 연구방법 : 전국 7개 장애인운전지원센터 중 2개 장애인운전지원센터에서 운전조력을 통해 운전면허를 취득한 장애인 488명에 대한 현황 및 항목별 빈도분석을 실시하였다. 결과 : 분석 결과, 개소 이후 2017년까지 2개 장애인운전지원센터에서 운전조력을 받고 운전면허를 취득한 장애인은 총 488명 이었으며, 장애유형별로는 지체장애 234명, 뇌병변장애 45명, 청각장애 151명, 발달장애 33명, 정신장애 3명, 기타장애 22명인 것으로 나타났다. 장애등급별로 확인해본 결과, 1급 60명, 2급 221명, 3급 207명인 것으로 나타났으며, 운전면허 취득 종별은 1종대형 19명, 1종보통 114명, 2종보통 353명, 1종특수 2명으로 확인되 었다. 결론 : 본 연구는 장애인운전지원센터 개소 이후, 운전면허를 취득한 장애인의현황 및 관련정보 제시하고, 이를 바탕으로 국내에 거주하는 장애인이 운전면허를 취득하는데 있어 개선사항을 도출하고자 하였다. 본 연구를 토대로 장애인이 운전면허를 취득하는데 있어 국가차원의제도적 개선 및 지원과 장애인 운전에 대한 인식변화가 이뤄지길 기대한다.

Advances in information technology, communication and network technology are radically facilitating digital convergences as the integration of human, equipment, and space in the current industry 4.0 era. In industry 4.0 environment, the vast amount of information with networked computing technology can be simultaneously accessible even in limited physical space. Two main benefit points out of these information are the convenience and efficiency in their online transactions either buying things online or selling online. Even though there exist so many benefits that information technology can create for the people doing business over the internet there is a critical problem to be answered. In spite of many such advantages, however, online transactions have many dysfunctions such as personal information leakage, account hacking, and cybercrime. Without preparing the appropriate protection methods or schema people reluctantly use the transaction or would find some other partners with enhanced information security environment. In this paper we suggested a novel selection criteria that can be used to evaluate the reliable means of authentication against the expected risks under on-going IoT based environment. Our selection criteria consists of 4 steps. The first step is services and risk identification step. The second step is evaluation of risk occurrence step. The third step includes the evaluation of the extent of damage. And the final step is the assessment of the level of risk. With the help of the above 4 step-approach people can systematically identify potential risks hiding in the online transactions and effectively avoid by taking appropriate counter actions

A thick film of Li7La3Zr2O12 (LLZO) solid-state electrolyte is fabricated using the tape casting process and is compared to a bulk specimen in terms of the density, microstructure, and ion conductivity. The final thickness of LLZO film after sintering is 240 μm which is stacked up with four sheets of LLZO green films including polymeric binders. The relative density of the LLZO film is 83%, which is almost the same as that of the bulk specimen. The ion conductivity of a LLZO thick film is 2.81 × 10−4 S/cm, which is also similar to that of the bulk specimen, 2.54 × 10−4 S/ cm. However, the microstructure shows a large difference in the grain size between the thick film and the bulk specimen. Although the grain boundary area is different between the thick film and the bulk specimen, the fact that both the ion conductivities are very similar means that no secondary phase exists at the grain boundary, which is thought to originate from nonstoichiometry or contamination.

In this paper we have tackled the outstanding inventory planning problems over new product launching period in a more holistic manner by addressing first the definition of efficient business rules to effectively control and reduce the inventory risks followed by the rigorous explanations on the implementation guide on suggested inventory planning rules. It is not unusual for many companies in the consumer electronics market to make a great effort to reduce the time to launch a new product because the ability to bring out higher performing products in such a short time period greatly increases the probability for them to remain competitive in the high tech market. Among so many newly developed products, those products with new features and technologies appeal to many potential customers while products which fail to win customers by design and prices rapidly disappear in the market. To adapt to this business environment, those companies have been trying to find the answer to minimize the inventory of old products so they can move to next generation products quickly with less obsolete material . In the experimental implementation of our rule-based inventory planning, Company ‘S’ reduced the inventory cost for the outgoing products as low as 49% of its peak level of its preceding product version in just 5 month after the adoption of rule-based inventory planning process and system. This paper concluded the subject with a suggestion that the best performance of rule-based inventory planning is guaranteed not from one-time campaign of process improvement along with system development but the decision maker’s continuing support and attention even without seeing any upcoming business crisis.

Rare-earth zirconates, such as lanthanum zirconates and gadolinium zirconates, have been intensively investigated due to their excellent properties of low thermal conductivity as well as chemical stability at high temperature, which can make these materials ones of the most promising candidates for next-generation thermal barrier coating applications. In this study, three compositions, lanthanum/gadolinium zirconates with reduced rare-earth contents from stoichiometric RE2Zr2O7 compositions, are fabricated via solid state reaction as well as sintering at 1600oC for 4 hrs. The phase formation, microstructure, and thermo-physical properties of three oxide ceramics are examined. In particular, each oxide ceramics exhibits composite structures between pyrochlore and fluorite phases. The potential of lanthanum/ gadolinium zirconate ceramics for TBC applications is also discussed.

Lanthanum zirconate, La2Zr2O7, is one of the most promising candidates for next-generation thermal barrier coating (TBC) applications in high efficient gas turbines due to its low thermal conductivity and chemical stability at high temperature. In this study, bulk specimens and thermal barrier coatings are fabricated via a variety of sintering processes as well as suspension plasma spray in lanthanum zirconates with reduced rare-earth contents. The phase formation, microstructure, and thermo-physical properties of these oxide ceramics and coatings are examined. In particular, lanthanum zirconates with reduced rare-earth contents in a La2Zr2O7-4YSZ composite system exhibit a single phase of fluorite or pyrochlore after fabricated by suspension plasma spray or spark plasma sintering. The potential of lanthanum zirconate ceramics for TBC applications is also discussed.

In this paper, even though there exist various problems to be solved in SCM field, we focus on problems arising from demand- supply discrepancy and introduce the concept of CPFR (Collaboration Planning Forecasting and Replenishment) as one solution for outstanding problems. Furthermore, by presenting a real CPFR project case between the S Company and V Company, we try to help potential benefactors of CPFR in two aspects : 1) how to implement CPFR, and 2) what they can expect from CPFR.

Constructions sites are affected by Diversity workplace, complexity of construction, Change of place, Mobility of workers and so on. In a single establishment, Prime contractors and subcontractors have to conduct their work at the same time. There are a lot of unpredictable risks when the construction is running, coordination between contractors is very important to do a risk assessment under the condition. Large Construction companies were investigated by previous studies. Survey research is applied to the risk assessment. In the writing, Risk assessment of the entire lower level. Because of the low level of risk factors to find. Also, There was a limit to investigate accidents. Confirmed that Effort to derive a risk factors were desperately of the risk assessment. Results were obtained through previous studies. The PCM is several experts should be joined. Experts Site Manager, Supervisor, Safety Manager, Director Contractor, Work team leader is required to participate. Construction plans, Process Planning to the risk find beforehand. And Determines how the operations and the control. Also, Made it into the database. and PCRA can be used in the risk assessment was developed.

The effects of particle size of Li-Si alloy and LiCl-KCl addition as a binder phase for raw material of anode were investigated on the formability of the thermal battery anode. The formability was evaluated with respect to filling density, tap density, compaction density, spring-back and compressive strength. With increasing particle size of Li-Si alloy powder, densities increased while spring-back and compressive strength decreased. Since the small spring-back is beneficial to avoiding breakage of pressed compacts, larger particles might be more suitable for anode forming. The increasing amount of LiCl-KCl binder phase contributed to reducing spring-back, improving the formability of anode powder too. The control of particle size also seems to be helpful to get double pressed pellets, which consisted of two layer of anode and electrolyte.

본 연구에서는 다양한 실내 온열환경 및 조도에서 재실자가 느끼는 조명에 대한 감성의 변화와 작업의 종류에 따라 생체신호를 분석하여 업무에 미치는 영향에 대해 살펴보고자 하였다. 이를 위해 실내 온열환경은 PMV(predicted mean vote) 지표 값을 기반으로 환경을 구성하였고, 조명환경은 LED광원을 이용한 스탠드를 통해 조명의 밝기에 변화를 주어 다양한 실내 환경을 구성하고 실험을 진행하였다. 주어진 환경에서 설문지를 통해 조명에 대한 감성을 평가하고 종류가 다른 오류검색수정 작업을 진행하면서 뇌파와 심전도를 측정하여 변화를 분석하였다. 그 결과, 작업의 종류에 대한 모든 생체신호는 온열환경의 변화와 유의적인 차이를 보였으며, PMV 지표 값이 0.8(온도: 25 ℃, 습도: 50 %)일 경우 집중력 및 주의력이 가장 활성화 되었다. 하지만, 조도의 변화에 는 대체적으로 유의적인 차이는 보이지 않았다. 따라서 재실자의 업무 능력에 미치는 집중력은 온열환경과 밀접 함을 확인할 수 있다. 또한, 조명에 대한 주관적인 감성은 조도가 낮을수록 편안함을 느꼈으며, 조도가 높을수록 불편함을 느꼈다. 하지만 온열환경의 변화에는 유의적인 차이가 없었다.

We show how a supplier can peg cost measures to the reliability of his time guarantees via the penalty costs considered in the framework. The framework also enables us to study the connections between the logistics network and the market. In this context, we show that even when the market base increases significantly, the supplier can still use the logistics network designed to satisfy lower demand density, with only a marginal reduction in profit. Finally we show how the framework is useful to evaluate and compare various logistics system improvement strategies. The supplier can then easily choose the improvement strategy that increases his profit with the minimal increase in his logistics costs.